1. Field of Technology
This application relates generally to wireless data devices in general, and to a method and apparatus for soliciting connectivity from wireless data networks, in particular.
2. Related Art
Mobile IP and simple IP are two wireless IP implementations that exist in current wireless networks. Presently, simple IP is more widely used than mobile IP, at least partly because IP addresses are a scarce yet expensive network resource, and simple IP allows the network to dynamically assign IP addresses to wireless data devices. Consider, for example, wireless devices utilizing a CDMA2000® Radio Access Network (RAN) and the like, wherein a Packet Data Serving Node (PDSN) acts as an access gateway, providing both simple IP and mobile IP access. In such CDMA2000 networks, simple IP currently dominates. Typical wireless networks that use simple IP have an inactivity timer, and in the case of CDMA2000 and the like, the inactivity timer is implemented at the PDSN.
The PDSN starts the inactivity timer once it detects that a wireless data device's data traffic stops. When the inactivity timer expires, the network recollects the IP addresses assigned to the wireless data device and may assign it to other wireless data devices as needed. This results in large resource savings on the network side. However the recollection of IP address results in the wireless data device losing data service privilege to the network. This may not be acceptable for a wireless data device that needs to be always-connected such as those designed to receive push services, as push devices may appear to be inactive from the point of view of the inactivity timer, while in fact they may be quietly awaiting push services from push data servers.
In order to meet the always-connected requirement for push devices, one technique has wireless data devices send keep-alive data messages to the push data servers at a fixed interval. The simple IP inactivity timer at the PDSN is thereby refreshed implicitly each time the keep-alive data messages pass through the PDSN. Two problems exist with this technique. First, it may cause extra traffic at the push data server. Second, multiple wireless data devices may send keep-alive messages simultaneously, which may overload the capacity of the wireless data network.